This present document relates to depth ambiguity artifact in ultrasound or pulse-echo imaging. If the pulse repetition interval (PRI) is not long enough to let the previous pulse attenuate sufficiently before firing the next pulse, echoes from deep echogenic objects interfere with the echoes from shallower objects. This creates images of deeper objects superimposed on the image of shallower objects. Such artifacts are known as depth ambiguity artifacts.
These artifacts are undesired, particularly for pelvic, OB and cardiac exams where the signal path includes low attenuation anechoic or hypo-echoic chambers. These chambers are displayed as black or uniform regions. However, the artifacts may be superimposed on the chamber region, resulting in an image showing tissue in a region without tissue.
A previous ultrasound imaging system allowed the user to manually verify the existence of depth ambiguity artifacts. A “Frame Rate” function allowed the user to increase the pulse repetition interval by 50%. This change in pulse repetition interval would slow the frame rate, but shift the location of any depth ambiguity artifacts. The user could then determine whether a structure in the image was an artifact from a deeper tissue. If the structure in the image moves to a different depth upon toggling the Frame Rate, the structure is an artifact. However, the slowed frame rate is not desired. Merely shifting the artifact still results in the artifact being in the image. Manual toggling requires effort by sonographers already very busy performing an ultrasound exam.